Parasitic leakage effects in electronic circuits and devices can result in unwanted and often detrimental spurious signals. Modern devices have become more and more sophisticated with the associated requirement for improved performance with respect to parasitic effects, as well as other performance characteristics, in amplifier and receiver circuits used, for example, in microwave and radio frequency (RF) applications.
RF filter devices built on semiconductor substrates, such as film-bulk acoustic resonators (FBARs), can be susceptible to leakage effects between traces and pads, especially between input and output pads due to intimate connection between the pads and the underlying semiconductor. FBARs manufactured in the manner of an acoustic resonator suspended over a cavity are also susceptible to leakage paths along the floor and walls of the cavity. Extraneous conduction paths can result in multiple deleterious effects, such as poor passband performance. Different types of conduction paths may exist, for example, substrate and surface conduction paths.